Merge all the enhancements and bug fixes from trunk, since none are

destablizing.  Call this the second beta.

FossilOrigin-Name: fb3ee1b7cac09e4950e4f48b44c277e4f391cb6c8f069644732d2389ca653da4

13 files changed, 1122 insertions, 773 deletions

diff --git a/src/btree.c b/src/btree.c
index 89222197b..ddcb6cfd3 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -4824,7 +4824,7 @@ static const void *fetchPayload(
   BtCursor *pCur,      /* Cursor pointing to entry to read from */
   u32 *pAmt            /* Write the number of available bytes here */
 ){
-  u32 amt;
+  int amt;
   assert( pCur!=0 && pCur->iPage>=0 && pCur->pPage);
   assert( pCur->eState==CURSOR_VALID );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
@@ -4833,9 +4833,14 @@ static const void *fetchPayload(
   assert( pCur->info.nSize>0 );
   assert( pCur->info.pPayload>pCur->pPage->aData || CORRUPT_DB );
   assert( pCur->info.pPayload<pCur->pPage->aDataEnd ||CORRUPT_DB);
-  amt = (int)(pCur->pPage->aDataEnd - pCur->info.pPayload);
-  if( pCur->info.nLocal<amt ) amt = pCur->info.nLocal;
-  *pAmt = amt;
+  amt = pCur->info.nLocal;
+  if( amt>(int)(pCur->pPage->aDataEnd - pCur->info.pPayload) ){
+    /* There is too little space on the page for the expected amount
+    ** of local content. Database must be corrupt. */
+    assert( CORRUPT_DB );
+    amt = MAX(0, (int)(pCur->pPage->aDataEnd - pCur->info.pPayload));
+  }
+  *pAmt = (u32)amt;
   return (void*)pCur->info.pPayload;
 }
 
diff --git a/src/build.c b/src/build.c
index cb8c374d1..a9428104a 100644
--- a/src/build.c
+++ b/src/build.c
@@ -1063,12 +1063,10 @@ void sqlite3AddColumn(Parse *pParse, Token *pName, Token *pType){
   Column *pCol;
   sqlite3 *db = pParse->db;
   if( (p = pParse->pNewTable)==0 ) return;
-#if SQLITE_MAX_COLUMN
   if( p->nCol+1>db->aLimit[SQLITE_LIMIT_COLUMN] ){
     sqlite3ErrorMsg(pParse, "too many columns on %s", p->zName);
     return;
   }
-#endif
   z = sqlite3DbMallocRaw(db, pName->n + pType->n + 2);
   if( z==0 ) return;
   memcpy(z, pName->z, pName->n);
diff --git a/src/dbpage.c b/src/dbpage.c
new file mode 100644
index 000000000..d21c5b6df
--- /dev/null
+++ b/src/dbpage.c
@@ -0,0 +1,329 @@
+/*
+** 2017-10-11
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains an implementation of the "sqlite_dbpage" virtual table.
+**
+** The sqlite_dbpage virtual table is used to read or write whole raw
+** pages of the database file.  The pager interface is used so that 
+** uncommitted changes and changes recorded in the WAL file are correctly
+** retrieved.
+**
+** Usage example:
+**
+**    SELECT data FROM sqlite_dbpage('aux1') WHERE pgno=123;
+**
+** This is an eponymous virtual table so it does not need to be created before
+** use.  The optional argument to the sqlite_dbpage() table name is the
+** schema for the database file that is to be read.  The default schema is
+** "main".
+**
+** The data field of sqlite_dbpage table can be updated.  The new
+** value must be a BLOB which is the correct page size, otherwise the
+** update fails.  Rows may not be deleted or inserted.
+*/
+
+#include "sqliteInt.h"   /* Requires access to internal data structures */
+#if (defined(SQLITE_ENABLE_DBPAGE_VTAB) || defined(SQLITE_TEST)) \
+    && !defined(SQLITE_OMIT_VIRTUALTABLE)
+
+typedef struct DbpageTable DbpageTable;
+typedef struct DbpageCursor DbpageCursor;
+
+struct DbpageCursor {
+  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
+  int pgno;                       /* Current page number */
+  int mxPgno;                     /* Last page to visit on this scan */
+};
+
+struct DbpageTable {
+  sqlite3_vtab base;              /* Base class.  Must be first */
+  sqlite3 *db;                    /* The database */
+  Pager *pPager;                  /* Pager being read/written */
+  int iDb;                        /* Index of database to analyze */
+  int szPage;                     /* Size of each page in bytes */
+  int nPage;                      /* Number of pages in the file */
+};
+
+/*
+** Connect to or create a dbpagevfs virtual table.
+*/
+static int dbpageConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc, const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  DbpageTable *pTab = 0;
+  int rc = SQLITE_OK;
+  int iDb;
+
+  if( argc>=4 ){
+    Token nm;
+    sqlite3TokenInit(&nm, (char*)argv[3]);
+    iDb = sqlite3FindDb(db, &nm);
+    if( iDb<0 ){
+      *pzErr = sqlite3_mprintf("no such schema: %s", argv[3]);
+      return SQLITE_ERROR;
+    }
+  }else{
+    iDb = 0;
+  }
+  rc = sqlite3_declare_vtab(db, 
+          "CREATE TABLE x(pgno INTEGER PRIMARY KEY, data BLOB, schema HIDDEN)");
+  if( rc==SQLITE_OK ){
+    pTab = (DbpageTable *)sqlite3_malloc64(sizeof(DbpageTable));
+    if( pTab==0 ) rc = SQLITE_NOMEM_BKPT;
+  }
+
+  assert( rc==SQLITE_OK || pTab==0 );
+  if( rc==SQLITE_OK ){
+    Btree *pBt = db->aDb[iDb].pBt;
+    memset(pTab, 0, sizeof(DbpageTable));
+    pTab->db = db;
+    pTab->iDb = iDb;
+    pTab->pPager = pBt ? sqlite3BtreePager(pBt) : 0;
+  }
+
+  *ppVtab = (sqlite3_vtab*)pTab;
+  return rc;
+}
+
+/*
+** Disconnect from or destroy a dbpagevfs virtual table.
+*/
+static int dbpageDisconnect(sqlite3_vtab *pVtab){
+  sqlite3_free(pVtab);
+  return SQLITE_OK;
+}
+
+/*
+** idxNum:
+**
+**     0     full table scan
+**     1     pgno=?1
+*/
+static int dbpageBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  int i;
+  pIdxInfo->estimatedCost = 1.0e6;  /* Initial cost estimate */
+  for(i=0; i<pIdxInfo->nConstraint; i++){
+    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i];
+    if( p->usable && p->iColumn<=0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+      pIdxInfo->estimatedRows = 1;
+      pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;
+      pIdxInfo->estimatedCost = 1.0;
+      pIdxInfo->idxNum = 1;
+      pIdxInfo->aConstraintUsage[i].argvIndex = 1;
+      pIdxInfo->aConstraintUsage[i].omit = 1;
+      break;
+    }
+  }
+  if( pIdxInfo->nOrderBy>=1
+   && pIdxInfo->aOrderBy[0].iColumn<=0
+   && pIdxInfo->aOrderBy[0].desc==0
+  ){
+    pIdxInfo->orderByConsumed = 1;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Open a new dbpagevfs cursor.
+*/
+static int dbpageOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
+  DbpageCursor *pCsr;
+
+  pCsr = (DbpageCursor *)sqlite3_malloc64(sizeof(DbpageCursor));
+  if( pCsr==0 ){
+    return SQLITE_NOMEM_BKPT;
+  }else{
+    memset(pCsr, 0, sizeof(DbpageCursor));
+    pCsr->base.pVtab = pVTab;
+    pCsr->pgno = -1;
+  }
+
+  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
+  return SQLITE_OK;
+}
+
+/*
+** Close a dbpagevfs cursor.
+*/
+static int dbpageClose(sqlite3_vtab_cursor *pCursor){
+  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
+  sqlite3_free(pCsr);
+  return SQLITE_OK;
+}
+
+/*
+** Move a dbpagevfs cursor to the next entry in the file.
+*/
+static int dbpageNext(sqlite3_vtab_cursor *pCursor){
+  int rc = SQLITE_OK;
+  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
+  pCsr->pgno++;
+  return rc;
+}
+
+static int dbpageEof(sqlite3_vtab_cursor *pCursor){
+  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
+  return pCsr->pgno > pCsr->mxPgno;
+}
+
+static int dbpageFilter(
+  sqlite3_vtab_cursor *pCursor, 
+  int idxNum, const char *idxStr,
+  int argc, sqlite3_value **argv
+){
+  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
+  DbpageTable *pTab = (DbpageTable *)pCursor->pVtab;
+  int rc = SQLITE_OK;
+  Btree *pBt = pTab->db->aDb[pTab->iDb].pBt;
+
+  pTab->szPage = sqlite3BtreeGetPageSize(pBt);
+  pTab->nPage = sqlite3BtreeLastPage(pBt);
+  if( idxNum==1 ){
+    pCsr->pgno = sqlite3_value_int(argv[0]);
+    if( pCsr->pgno<1 || pCsr->pgno>pTab->nPage ){
+      pCsr->pgno = 1;
+      pCsr->mxPgno = 0;
+    }else{
+      pCsr->mxPgno = pCsr->pgno;
+    }
+  }else{
+    pCsr->pgno = 1;
+    pCsr->mxPgno = pTab->nPage;
+  }
+  return rc;
+}
+
+static int dbpageColumn(
+  sqlite3_vtab_cursor *pCursor, 
+  sqlite3_context *ctx, 
+  int i
+){
+  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
+  DbpageTable *pTab = (DbpageTable *)pCursor->pVtab;
+  int rc = SQLITE_OK;
+  switch( i ){
+    case 0: {           /* pgno */
+      sqlite3_result_int(ctx, pCsr->pgno);
+      break;
+    }
+    case 1: {           /* data */
+      DbPage *pDbPage = 0;
+      rc = sqlite3PagerGet(pTab->pPager, pCsr->pgno, (DbPage**)&pDbPage, 0);
+      if( rc==SQLITE_OK ){
+        sqlite3_result_blob(ctx, sqlite3PagerGetData(pDbPage), pTab->szPage,
+                            SQLITE_TRANSIENT);
+      }
+      sqlite3PagerUnref(pDbPage);
+      break;
+    }
+    default: {          /* schema */
+      sqlite3 *db = sqlite3_context_db_handle(ctx);
+      sqlite3_result_text(ctx, db->aDb[pTab->iDb].zDbSName, -1, SQLITE_STATIC);
+      break;
+    }
+  }
+  return SQLITE_OK;
+}
+
+static int dbpageRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
+  DbpageCursor *pCsr = (DbpageCursor *)pCursor;
+  *pRowid = pCsr->pgno;
+  return SQLITE_OK;
+}
+
+static int dbpageUpdate(
+  sqlite3_vtab *pVtab,
+  int argc,
+  sqlite3_value **argv,
+  sqlite_int64 *pRowid
+){
+  DbpageTable *pTab = (DbpageTable *)pVtab;
+  int pgno;
+  DbPage *pDbPage = 0;
+  int rc = SQLITE_OK;
+  char *zErr = 0;
+
+  if( argc==1 ){
+    zErr = "cannot delete";
+    goto update_fail;
+  }
+  pgno = sqlite3_value_int(argv[0]);
+  if( pgno<1 || pgno>pTab->nPage ){
+    zErr = "bad page number";
+    goto update_fail;
+  }
+  if( sqlite3_value_int(argv[1])!=pgno ){
+    zErr = "cannot insert";
+    goto update_fail;
+  }
+  if( sqlite3_value_type(argv[3])!=SQLITE_BLOB 
+   || sqlite3_value_bytes(argv[3])!=pTab->szPage 
+  ){
+    zErr = "bad page value";
+    goto update_fail;
+  }
+  rc = sqlite3PagerGet(pTab->pPager, pgno, (DbPage**)&pDbPage, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3PagerWrite(pDbPage);
+    if( rc==SQLITE_OK ){
+      memcpy(sqlite3PagerGetData(pDbPage),
+             sqlite3_value_blob(argv[3]),
+             pTab->szPage);
+    }
+  }
+  sqlite3PagerUnref(pDbPage);
+  return rc;
+
+update_fail:
+  sqlite3_free(pVtab->zErrMsg);
+  pVtab->zErrMsg = sqlite3_mprintf("%s", zErr);
+  return SQLITE_ERROR;
+}
+
+/*
+** Invoke this routine to register the "dbpage" virtual table module
+*/
+int sqlite3DbpageRegister(sqlite3 *db){
+  static sqlite3_module dbpage_module = {
+    0,                            /* iVersion */
+    dbpageConnect,                /* xCreate */
+    dbpageConnect,                /* xConnect */
+    dbpageBestIndex,              /* xBestIndex */
+    dbpageDisconnect,             /* xDisconnect */
+    dbpageDisconnect,             /* xDestroy */
+    dbpageOpen,                   /* xOpen - open a cursor */
+    dbpageClose,                  /* xClose - close a cursor */
+    dbpageFilter,                 /* xFilter - configure scan constraints */
+    dbpageNext,                   /* xNext - advance a cursor */
+    dbpageEof,                    /* xEof - check for end of scan */
+    dbpageColumn,                 /* xColumn - read data */
+    dbpageRowid,                  /* xRowid - read data */
+    dbpageUpdate,                 /* xUpdate */
+    0,                            /* xBegin */
+    0,                            /* xSync */
+    0,                            /* xCommit */
+    0,                            /* xRollback */
+    0,                            /* xFindMethod */
+    0,                            /* xRename */
+    0,                            /* xSavepoint */
+    0,                            /* xRelease */
+    0,                            /* xRollbackTo */
+  };
+  return sqlite3_create_module(db, "sqlite_dbpage", &dbpage_module, 0);
+}
+#elif defined(SQLITE_ENABLE_DBPAGE_VTAB)
+int sqlite3DbpageRegister(sqlite3 *db){ return SQLITE_OK; }
+#endif /* SQLITE_ENABLE_DBSTAT_VTAB */
diff --git a/src/main.c b/src/main.c
index 3d7609ce5..49613f6c7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3054,6 +3054,12 @@ static int openDatabase(
   }
 #endif
 
+#ifdef SQLITE_ENABLE_DBPAGE_VTAB
+  if( !db->mallocFailed && rc==SQLITE_OK){
+    rc = sqlite3DbpageRegister(db);
+  }
+#endif
+
 #ifdef SQLITE_ENABLE_DBSTAT_VTAB
   if( !db->mallocFailed && rc==SQLITE_OK){
     rc = sqlite3DbstatRegister(db);
diff --git a/src/resolve.c b/src/resolve.c
index 78f37512a..4a1e8284c 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -959,12 +959,10 @@ static int resolveCompoundOrderBy(
   pOrderBy = pSelect->pOrderBy;
   if( pOrderBy==0 ) return 0;
   db = pParse->db;
-#if SQLITE_MAX_COLUMN
   if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
     sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
     return 1;
   }
-#endif
   for(i=0; i<pOrderBy->nExpr; i++){
     pOrderBy->a[i].done = 0;
   }
@@ -1056,12 +1054,10 @@ int sqlite3ResolveOrderGroupBy(
   struct ExprList_item *pItem;
 
   if( pOrderBy==0 || pParse->db->mallocFailed ) return 0;
-#if SQLITE_MAX_COLUMN
   if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
     sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
     return 1;
   }
-#endif
   pEList = pSelect->pEList;
   assert( pEList!=0 );  /* sqlite3SelectNew() guarantees this */
   for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
diff --git a/src/select.c b/src/select.c
index 6f524fa2e..0e2328120 100644
--- a/src/select.c
+++ b/src/select.c
@@ -1689,6 +1689,7 @@ int sqlite3ColumnsFromExprList(
     nCol = pEList->nExpr;
     aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
     testcase( aCol==0 );
+    if( nCol>32767 ) nCol = 32767;
   }else{
     nCol = 0;
     aCol = 0;
@@ -4596,12 +4597,10 @@ static int selectExpander(Walker *pWalker, Select *p){
     sqlite3ExprListDelete(db, pEList);
     p->pEList = pNew;
   }
-#if SQLITE_MAX_COLUMN
   if( p->pEList && p->pEList->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){
     sqlite3ErrorMsg(pParse, "too many columns in result set");
     return WRC_Abort;
   }
-#endif
   return WRC_Continue;
 }
 
diff --git a/src/shell.c.in b/src/shell.c.in
index 896d475ed..8f5ed59e9 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -3611,20 +3611,24 @@ static int shell_dbinfo_command(ShellState *p, int nArg, char **azArg){
      { "schema size:",
        "SELECT total(length(sql)) FROM %s" },
   };
-  sqlite3_file *pFile = 0;
   int i;
   char *zSchemaTab;
   char *zDb = nArg>=2 ? azArg[1] : "main";
+  sqlite3_stmt *pStmt = 0;
   unsigned char aHdr[100];
   open_db(p, 0);
   if( p->db==0 ) return 1;
-  sqlite3_file_control(p->db, zDb, SQLITE_FCNTL_FILE_POINTER, &pFile);
-  if( pFile==0 || pFile->pMethods==0 || pFile->pMethods->xRead==0 ){
-    return 1;
-  }
-  i = pFile->pMethods->xRead(pFile, aHdr, 100, 0);
-  if( i!=SQLITE_OK ){
+  sqlite3_prepare_v2(p->db,"SELECT data FROM sqlite_dbpage(?1) WHERE pgno=1",
+                     -1, &pStmt, 0);
+  sqlite3_bind_text(pStmt, 1, zDb, -1, SQLITE_STATIC);
+  if( sqlite3_step(pStmt)==SQLITE_ROW
+   && sqlite3_column_bytes(pStmt,0)>100
+  ){
+    memcpy(aHdr, sqlite3_column_blob(pStmt,0), 100);
+    sqlite3_finalize(pStmt);
+  }else{
     raw_printf(stderr, "unable to read database header\n");
+    sqlite3_finalize(pStmt);
     return 1;
   }
   i = get2byteInt(aHdr+16);
@@ -4244,7 +4248,7 @@ static int do_meta_command(char *zLine, ShellState *p){
       utf8_printf(stderr,
                  "testcase-%s FAILED\n Expected: [%s]\n      Got: [%s]\n",
                  p->zTestcase, azArg[1], zRes);
-      rc = 2;
+      rc = 1;
     }else{
       utf8_printf(stdout, "testcase-%s ok\n", p->zTestcase);
       p->nCheck++;
diff --git a/src/sqlite3ext.h b/src/sqlite3ext.h
index 4aade278b..d1d2c574a 100644
--- a/src/sqlite3ext.h
+++ b/src/sqlite3ext.h
@@ -134,7 +134,7 @@ struct sqlite3_api_routines {
   int  (*set_authorizer)(sqlite3*,int(*)(void*,int,const char*,const char*,
                          const char*,const char*),void*);
   void  (*set_auxdata)(sqlite3_context*,int,void*,void (*)(void*));
-  char * (*snprintf)(int,char*,const char*,...);
+  char * (*xsnprintf)(int,char*,const char*,...);
   int  (*step)(sqlite3_stmt*);
   int  (*table_column_metadata)(sqlite3*,const char*,const char*,const char*,
                                 char const**,char const**,int*,int*,int*);
@@ -418,7 +418,7 @@ typedef int (*sqlite3_loadext_entry)(
 #define sqlite3_rollback_hook          sqlite3_api->rollback_hook
 #define sqlite3_set_authorizer         sqlite3_api->set_authorizer
 #define sqlite3_set_auxdata            sqlite3_api->set_auxdata
-#define sqlite3_snprintf               sqlite3_api->snprintf
+#define sqlite3_snprintf               sqlite3_api->xsnprintf
 #define sqlite3_step                   sqlite3_api->step
 #define sqlite3_table_column_metadata  sqlite3_api->table_column_metadata
 #define sqlite3_thread_cleanup         sqlite3_api->thread_cleanup
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index a8f1bed51..0cc435d7b 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -4400,6 +4400,9 @@ int sqlite3ThreadCreate(SQLiteThread**,void*(*)(void*),void*);
 int sqlite3ThreadJoin(SQLiteThread*, void**);
 #endif
 
+#if defined(SQLITE_ENABLE_DBPAGE_VTAB) || defined(SQLITE_TEST)
+int sqlite3DbpageRegister(sqlite3*);
+#endif
 #if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)
 int sqlite3DbstatRegister(sqlite3*);
 #endif
diff --git a/src/tclsqlite.c b/src/tclsqlite.c
index 1b9f91405..eed86eee3 100644
--- a/src/tclsqlite.c
+++ b/src/tclsqlite.c
@@ -14,17 +14,19 @@
 **
 ** Compile-time options:
 **
-**  -DTCLSH=1             Add a "main()" routine that works as a tclsh.
+**  -DTCLSH         Add a "main()" routine that works as a tclsh.
 **
-**  -DSQLITE_TCLMD5       When used in conjuction with -DTCLSH=1, add
-**                        four new commands to the TCL interpreter for
-**                        generating MD5 checksums:  md5, md5file,
-**                        md5-10x8, and md5file-10x8.
+**  -DTCLSH_INIT_PROC=name
 **
-**  -DSQLITE_TEST         When used in conjuction with -DTCLSH=1, add
-**                        hundreds of new commands used for testing
-**                        SQLite.  This option implies -DSQLITE_TCLMD5.
-*/
+**                  Invoke name(interp) to initialize the Tcl interpreter.
+**                  If name(interp) returns a non-NULL string, then run
+**                  that string as a Tcl script to launch the application.
+**                  If name(interp) returns NULL, then run the regular
+**                  tclsh-emulator code.
+*/
+#ifdef TCLSH_INIT_PROC
+# define TCLSH 1
+#endif
 
 /*
 ** If requested, include the SQLite compiler options file for MSVC.
@@ -3286,7 +3288,42 @@ static int SQLITE_TCLAPI DbObjCmd(
   ** Return the version string for this database.
   */
   case DB_VERSION: {
-    Tcl_SetResult(interp, (char *)sqlite3_libversion(), TCL_STATIC);
+    int i;
+    for(i=2; i<objc; i++){
+      const char *zArg = Tcl_GetString(objv[i]);
+      /* Optional arguments to $db version are used for testing purpose */
+#ifdef SQLITE_TEST
+      /* $db version -use-legacy-prepare BOOLEAN
+      **
+      ** Turn the use of legacy sqlite3_prepare() on or off.
+      */
+      if( strcmp(zArg, "-use-legacy-prepare")==0 && i+1<objc ){
+        i++;
+        if( Tcl_GetBooleanFromObj(interp, objv[i], &pDb->bLegacyPrepare) ){
+          return TCL_ERROR;
+        }
+      }else
+
+      /* $db version -last-stmt-ptr
+      **
+      ** Return a string which is a hex encoding of the pointer to the
+      ** most recent sqlite3_stmt in the statement cache.
+      */
+      if( strcmp(zArg, "-last-stmt-ptr")==0 ){
+        char zBuf[100];
+        sqlite3_snprintf(sizeof(zBuf), zBuf, "%p",
+                         pDb->stmtList ? pDb->stmtList->pStmt: 0);
+        Tcl_SetResult(interp, zBuf, TCL_VOLATILE);
+      }else
+#endif /* SQLITE_TEST */
+      {
+        Tcl_AppendResult(interp, "unknown argument: ", zArg, (char*)0);
+        return TCL_ERROR;
+      }
+    }
+    if( i==2 ){   
+      Tcl_SetResult(interp, (char *)sqlite3_libversion(), TCL_STATIC);
+    }
     break;
   }
 
@@ -3546,721 +3583,56 @@ int Sqlite_Unload(Tcl_Interp *interp, int flags){ return TCL_OK; }
 int Tclsqlite_Unload(Tcl_Interp *interp, int flags){ return TCL_OK; }
 #endif
 
-#ifdef TCLSH
-/*****************************************************************************
-** All of the code that follows is used to build standalone TCL interpreters
-** that are statically linked with SQLite.  Enable these by compiling
-** with -DTCLSH=n where n can be 1 or 2.  An n of 1 generates a standard
-** tclsh but with SQLite built in.  An n of 2 generates the SQLite space
-** analysis program.
-*/
-
-#if defined(SQLITE_TEST) || defined(SQLITE_TCLMD5)
-/*
- * This code implements the MD5 message-digest algorithm.
- * The algorithm is due to Ron Rivest.  This code was
- * written by Colin Plumb in 1993, no copyright is claimed.
- * This code is in the public domain; do with it what you wish.
- *
- * Equivalent code is available from RSA Data Security, Inc.
- * This code has been tested against that, and is equivalent,
- * except that you don't need to include two pages of legalese
- * with every copy.
- *
- * To compute the message digest of a chunk of bytes, declare an
- * MD5Context structure, pass it to MD5Init, call MD5Update as
- * needed on buffers full of bytes, and then call MD5Final, which
- * will fill a supplied 16-byte array with the digest.
- */
-
-/*
- * If compiled on a machine that doesn't have a 32-bit integer,
- * you just set "uint32" to the appropriate datatype for an
- * unsigned 32-bit integer.  For example:
- *
- *       cc -Duint32='unsigned long' md5.c
- *
- */
-#ifndef uint32
-#  define uint32 unsigned int
-#endif
-
-struct MD5Context {
-  int isInit;
-  uint32 buf[4];
-  uint32 bits[2];
-  unsigned char in[64];
-};
-typedef struct MD5Context MD5Context;
-
-/*
- * Note: this code is harmless on little-endian machines.
- */
-static void byteReverse (unsigned char *buf, unsigned longs){
-        uint32 t;
-        do {
-                t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
-                            ((unsigned)buf[1]<<8 | buf[0]);
-                *(uint32 *)buf = t;
-                buf += 4;
-        } while (--longs);
-}
-/* The four core functions - F1 is optimized somewhat */
-
-/* #define F1(x, y, z) (x & y | ~x & z) */
-#define F1(x, y, z) (z ^ (x & (y ^ z)))
-#define F2(x, y, z) F1(z, x, y)
-#define F3(x, y, z) (x ^ y ^ z)
-#define F4(x, y, z) (y ^ (x | ~z))
-
-/* This is the central step in the MD5 algorithm. */
-#define MD5STEP(f, w, x, y, z, data, s) \
-        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
-
-/*
- * The core of the MD5 algorithm, this alters an existing MD5 hash to
- * reflect the addition of 16 longwords of new data.  MD5Update blocks
- * the data and converts bytes into longwords for this routine.
- */
-static void MD5Transform(uint32 buf[4], const uint32 in[16]){
-        register uint32 a, b, c, d;
-
-        a = buf[0];
-        b = buf[1];
-        c = buf[2];
-        d = buf[3];
-
-        MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
-        MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
-        MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
-        MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
-        MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
-        MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
-        MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
-        MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
-        MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
-        MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
-        MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
-        MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
-        MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
-        MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
-        MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
-        MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
-
-        MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
-        MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
-        MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
-        MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
-        MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
-        MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
-        MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
-        MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
-        MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
-        MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
-        MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
-        MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
-        MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
-        MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
-        MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
-        MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
-
-        MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
-        MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
-        MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
-        MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
-        MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
-        MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
-        MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
-        MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
-        MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
-        MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
-        MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
-        MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
-        MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
-        MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
-        MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
-        MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
-
-        MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
-        MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
-        MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
-        MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
-        MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
-        MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
-        MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
-        MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
-        MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
-        MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
-        MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
-        MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
-        MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
-        MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
-        MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
-        MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
-
-        buf[0] += a;
-        buf[1] += b;
-        buf[2] += c;
-        buf[3] += d;
-}
-
-/*
- * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
- * initialization constants.
- */
-static void MD5Init(MD5Context *ctx){
-        ctx->isInit = 1;
-        ctx->buf[0] = 0x67452301;
-        ctx->buf[1] = 0xefcdab89;
-        ctx->buf[2] = 0x98badcfe;
-        ctx->buf[3] = 0x10325476;
-        ctx->bits[0] = 0;
-        ctx->bits[1] = 0;
-}
-
-/*
- * Update context to reflect the concatenation of another buffer full
- * of bytes.
- */
-static
-void MD5Update(MD5Context *ctx, const unsigned char *buf, unsigned int len){
-        uint32 t;
-
-        /* Update bitcount */
-
-        t = ctx->bits[0];
-        if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
-                ctx->bits[1]++; /* Carry from low to high */
-        ctx->bits[1] += len >> 29;
-
-        t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
-
-        /* Handle any leading odd-sized chunks */
-
-        if ( t ) {
-                unsigned char *p = (unsigned char *)ctx->in + t;
-
-                t = 64-t;
-                if (len < t) {
-                        memcpy(p, buf, len);
-                        return;
-                }
-                memcpy(p, buf, t);
-                byteReverse(ctx->in, 16);
-                MD5Transform(ctx->buf, (uint32 *)ctx->in);
-                buf += t;
-                len -= t;
-        }
-
-        /* Process data in 64-byte chunks */
-
-        while (len >= 64) {
-                memcpy(ctx->in, buf, 64);
-                byteReverse(ctx->in, 16);
-                MD5Transform(ctx->buf, (uint32 *)ctx->in);
-                buf += 64;
-                len -= 64;
-        }
-
-        /* Handle any remaining bytes of data. */
-
-        memcpy(ctx->in, buf, len);
-}
-
-/*
- * Final wrapup - pad to 64-byte boundary with the bit pattern
- * 1 0* (64-bit count of bits processed, MSB-first)
- */
-static void MD5Final(unsigned char digest[16], MD5Context *ctx){
-        unsigned count;
-        unsigned char *p;
-
-        /* Compute number of bytes mod 64 */
-        count = (ctx->bits[0] >> 3) & 0x3F;
-
-        /* Set the first char of padding to 0x80.  This is safe since there is
-           always at least one byte free */
-        p = ctx->in + count;
-        *p++ = 0x80;
-
-        /* Bytes of padding needed to make 64 bytes */
-        count = 64 - 1 - count;
-
-        /* Pad out to 56 mod 64 */
-        if (count < 8) {
-                /* Two lots of padding:  Pad the first block to 64 bytes */
-                memset(p, 0, count);
-                byteReverse(ctx->in, 16);
-                MD5Transform(ctx->buf, (uint32 *)ctx->in);
-
-                /* Now fill the next block with 56 bytes */
-                memset(ctx->in, 0, 56);
-        } else {
-                /* Pad block to 56 bytes */
-                memset(p, 0, count-8);
-        }
-        byteReverse(ctx->in, 14);
-
-        /* Append length in bits and transform */
-        memcpy(ctx->in + 14*4, ctx->bits, 8);
-
-        MD5Transform(ctx->buf, (uint32 *)ctx->in);
-        byteReverse((unsigned char *)ctx->buf, 4);
-        memcpy(digest, ctx->buf, 16);
-}
-
 /*
-** Convert a 128-bit MD5 digest into a 32-digit base-16 number.
+** If the TCLSH macro is defined, add code to make a stand-alone program.
 */
-static void MD5DigestToBase16(unsigned char *digest, char *zBuf){
-  static char const zEncode[] = "0123456789abcdef";
-  int i, j;
-
-  for(j=i=0; i<16; i++){
-    int a = digest[i];
-    zBuf[j++] = zEncode[(a>>4)&0xf];
-    zBuf[j++] = zEncode[a & 0xf];
-  }
-  zBuf[j] = 0;
-}
-
+#if defined(TCLSH)
 
-/*
-** Convert a 128-bit MD5 digest into sequency of eight 5-digit integers
-** each representing 16 bits of the digest and separated from each
-** other by a "-" character.
+/* This is the main routine for an ordinary TCL shell.  If there are
+** are arguments, run the first argument as a script.  Otherwise,
+** read TCL commands from standard input
 */
-static void MD5DigestToBase10x8(unsigned char digest[16], char zDigest[50]){
-  int i, j;
-  unsigned int x;
-  for(i=j=0; i<16; i+=2){
-    x = digest[i]*256 + digest[i+1];
-    if( i>0 ) zDigest[j++] = '-';
-    sqlite3_snprintf(50-j, &zDigest[j], "%05u", x);
-    j += 5;
-  }
-  zDigest[j] = 0;
-}
-
-/*
-** A TCL command for md5.  The argument is the text to be hashed.  The
-** Result is the hash in base64.
-*/
-static int SQLITE_TCLAPI md5_cmd(
-  void*cd,
-  Tcl_Interp *interp,
-  int argc,
-  const char **argv
-){
-  MD5Context ctx;
-  unsigned char digest[16];
-  char zBuf[50];
-  void (*converter)(unsigned char*, char*);
-
-  if( argc!=2 ){
-    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
-        " TEXT\"", (char*)0);
-    return TCL_ERROR;
-  }
-  MD5Init(&ctx);
-  MD5Update(&ctx, (unsigned char*)argv[1], (unsigned)strlen(argv[1]));
-  MD5Final(digest, &ctx);
-  converter = (void(*)(unsigned char*,char*))cd;
-  converter(digest, zBuf);
-  Tcl_AppendResult(interp, zBuf, (char*)0);
-  return TCL_OK;
-}
-
-/*
-** A TCL command to take the md5 hash of a file.  The argument is the
-** name of the file.
-*/
-static int SQLITE_TCLAPI md5file_cmd(
-  void*cd,
-  Tcl_Interp *interp,
-  int argc,
-  const char **argv
-){
-  FILE *in;
-  int ofst;
-  int amt;
-  MD5Context ctx;
-  void (*converter)(unsigned char*, char*);
-  unsigned char digest[16];
-  char zBuf[10240];
-
-  if( argc!=2 && argc!=4 ){
-    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
-        " FILENAME [OFFSET AMT]\"", (char*)0);
-    return TCL_ERROR;
-  }
-  if( argc==4 ){
-    ofst = atoi(argv[2]);
-    amt = atoi(argv[3]);
-  }else{
-    ofst = 0;
-    amt = 2147483647;
-  }
-  in = fopen(argv[1],"rb");
-  if( in==0 ){
-    Tcl_AppendResult(interp,"unable to open file \"", argv[1],
-         "\" for reading", (char*)0);
-    return TCL_ERROR;
-  }
-  fseek(in, ofst, SEEK_SET);
-  MD5Init(&ctx);
-  while( amt>0 ){
-    int n;
-    n = (int)fread(zBuf, 1, sizeof(zBuf)<=amt ? sizeof(zBuf) : amt, in);
-    if( n<=0 ) break;
-    MD5Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
-    amt -= n;
-  }
-  fclose(in);
-  MD5Final(digest, &ctx);
-  converter = (void(*)(unsigned char*,char*))cd;
-  converter(digest, zBuf);
-  Tcl_AppendResult(interp, zBuf, (char*)0);
-  return TCL_OK;
-}
-
-/*
-** Register the four new TCL commands for generating MD5 checksums
-** with the TCL interpreter.
-*/
-int Md5_Init(Tcl_Interp *interp){
-  Tcl_CreateCommand(interp, "md5", (Tcl_CmdProc*)md5_cmd,
-                    MD5DigestToBase16, 0);
-  Tcl_CreateCommand(interp, "md5-10x8", (Tcl_CmdProc*)md5_cmd,
-                    MD5DigestToBase10x8, 0);
-  Tcl_CreateCommand(interp, "md5file", (Tcl_CmdProc*)md5file_cmd,
-                    MD5DigestToBase16, 0);
-  Tcl_CreateCommand(interp, "md5file-10x8", (Tcl_CmdProc*)md5file_cmd,
-                    MD5DigestToBase10x8, 0);
-  return TCL_OK;
-}
-#endif /* defined(SQLITE_TEST) || defined(SQLITE_TCLMD5) */
-
-#if defined(SQLITE_TEST)
-/*
-** During testing, the special md5sum() aggregate function is available.
-** inside SQLite.  The following routines implement that function.
-*/
-static void md5step(sqlite3_context *context, int argc, sqlite3_value **argv){
-  MD5Context *p;
-  int i;
-  if( argc<1 ) return;
-  p = sqlite3_aggregate_context(context, sizeof(*p));
-  if( p==0 ) return;
-  if( !p->isInit ){
-    MD5Init(p);
-  }
-  for(i=0; i<argc; i++){
-    const char *zData = (char*)sqlite3_value_text(argv[i]);
-    if( zData ){
-      MD5Update(p, (unsigned char*)zData, (int)strlen(zData));
-    }
-  }
-}
-static void md5finalize(sqlite3_context *context){
-  MD5Context *p;
-  unsigned char digest[16];
-  char zBuf[33];
-  p = sqlite3_aggregate_context(context, sizeof(*p));
-  MD5Final(digest,p);
-  MD5DigestToBase16(digest, zBuf);
-  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
-}
-int Md5_Register(
-  sqlite3 *db,
-  char **pzErrMsg,
-  const sqlite3_api_routines *pThunk
-){
-  int rc = sqlite3_create_function(db, "md5sum", -1, SQLITE_UTF8, 0, 0,
-                                 md5step, md5finalize);
-  sqlite3_overload_function(db, "md5sum", -1);  /* To exercise this API */
-  return rc;
-}
-#endif /* defined(SQLITE_TEST) */
-
-
-/*
-** If the macro TCLSH is one, then put in code this for the
-** "main" routine that will initialize Tcl and take input from
-** standard input, or if a file is named on the command line
-** the TCL interpreter reads and evaluates that file.
-*/
-#if TCLSH==1
 static const char *tclsh_main_loop(void){
   static const char zMainloop[] =
-    "set line {}\n"
-    "while {![eof stdin]} {\n"
-      "if {$line!=\"\"} {\n"
-        "puts -nonewline \"> \"\n"
-      "} else {\n"
-        "puts -nonewline \"% \"\n"
-      "}\n"
-      "flush stdout\n"
-      "append line [gets stdin]\n"
-      "if {[info complete $line]} {\n"
-        "if {[catch {uplevel #0 $line} result]} {\n"
-          "puts stderr \"Error: $result\"\n"
-        "} elseif {$result!=\"\"} {\n"
-          "puts $result\n"
+    "if {[llength $argv]>=1} {\n"
+      "set argv0 [lindex $argv 0]\n"
+      "set argv [lrange $argv 1 end]\n"
+      "source $argv0\n"
+    "} else {\n"
+      "set line {}\n"
+      "while {![eof stdin]} {\n"
+        "if {$line!=\"\"} {\n"
+          "puts -nonewline \"> \"\n"
+        "} else {\n"
+          "puts -nonewline \"% \"\n"
+        "}\n"
+        "flush stdout\n"
+        "append line [gets stdin]\n"
+        "if {[info complete $line]} {\n"
+          "if {[catch {uplevel #0 $line} result]} {\n"
+            "puts stderr \"Error: $result\"\n"
+          "} elseif {$result!=\"\"} {\n"
+            "puts $result\n"
+          "}\n"
+          "set line {}\n"
+        "} else {\n"
+          "append line \\n\n"
         "}\n"
-        "set line {}\n"
-      "} else {\n"
-        "append line \\n\n"
       "}\n"
     "}\n"
   ;
   return zMainloop;
 }
-#endif
-#if TCLSH==2
-static const char *tclsh_main_loop(void);
-#endif
-
-#ifdef SQLITE_TEST
-static void init_all(Tcl_Interp *);
-static int SQLITE_TCLAPI init_all_cmd(
-  ClientData cd,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-
-  Tcl_Interp *slave;
-  if( objc!=2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "SLAVE");
-    return TCL_ERROR;
-  }
-
-  slave = Tcl_GetSlave(interp, Tcl_GetString(objv[1]));
-  if( !slave ){
-    return TCL_ERROR;
-  }
-
-  init_all(slave);
-  return TCL_OK;
-}
-
-/*
-** Tclcmd: db_use_legacy_prepare DB BOOLEAN
-**
-**   The first argument to this command must be a database command created by
-**   [sqlite3]. If the second argument is true, then the handle is configured
-**   to use the sqlite3_prepare_v2() function to prepare statements. If it
-**   is false, sqlite3_prepare().
-*/
-static int SQLITE_TCLAPI db_use_legacy_prepare_cmd(
-  ClientData cd,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  Tcl_CmdInfo cmdInfo;
-  SqliteDb *pDb;
-  int bPrepare;
-
-  if( objc!=3 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "DB BOOLEAN");
-    return TCL_ERROR;
-  }
-
-  if( !Tcl_GetCommandInfo(interp, Tcl_GetString(objv[1]), &cmdInfo) ){
-    Tcl_AppendResult(interp, "no such db: ", Tcl_GetString(objv[1]), (char*)0);
-    return TCL_ERROR;
-  }
-  pDb = (SqliteDb*)cmdInfo.objClientData;
-  if( Tcl_GetBooleanFromObj(interp, objv[2], &bPrepare) ){
-    return TCL_ERROR;
-  }
-
-  pDb->bLegacyPrepare = bPrepare;
-
-  Tcl_ResetResult(interp);
-  return TCL_OK;
-}
-
-/*
-** Tclcmd: db_last_stmt_ptr DB
-**
-**   If the statement cache associated with database DB is not empty,
-**   return the text representation of the most recently used statement
-**   handle.
-*/
-static int SQLITE_TCLAPI db_last_stmt_ptr(
-  ClientData cd,
-  Tcl_Interp *interp,
-  int objc,
-  Tcl_Obj *CONST objv[]
-){
-  extern int sqlite3TestMakePointerStr(Tcl_Interp*, char*, void*);
-  Tcl_CmdInfo cmdInfo;
-  SqliteDb *pDb;
-  sqlite3_stmt *pStmt = 0;
-  char zBuf[100];
-
-  if( objc!=2 ){
-    Tcl_WrongNumArgs(interp, 1, objv, "DB");
-    return TCL_ERROR;
-  }
-
-  if( !Tcl_GetCommandInfo(interp, Tcl_GetString(objv[1]), &cmdInfo) ){
-    Tcl_AppendResult(interp, "no such db: ", Tcl_GetString(objv[1]), (char*)0);
-    return TCL_ERROR;
-  }
-  pDb = (SqliteDb*)cmdInfo.objClientData;
-
-  if( pDb->stmtList ) pStmt = pDb->stmtList->pStmt;
-  if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ){
-    return TCL_ERROR;
-  }
-  Tcl_SetResult(interp, zBuf, TCL_VOLATILE);
-
-  return TCL_OK;
-}
-#endif /* SQLITE_TEST */
-
-/*
-** Configure the interpreter passed as the first argument to have access
-** to the commands and linked variables that make up:
-**
-**   * the [sqlite3] extension itself,
-**
-**   * If SQLITE_TCLMD5 or SQLITE_TEST is defined, the Md5 commands, and
-**
-**   * If SQLITE_TEST is set, the various test interfaces used by the Tcl
-**     test suite.
-*/
-static void init_all(Tcl_Interp *interp){
-  Sqlite3_Init(interp);
-
-#if defined(SQLITE_TEST) || defined(SQLITE_TCLMD5)
-  Md5_Init(interp);
-#endif
-
-#ifdef SQLITE_TEST
-  {
-    extern int Sqliteconfig_Init(Tcl_Interp*);
-    extern int Sqlitetest1_Init(Tcl_Interp*);
-    extern int Sqlitetest2_Init(Tcl_Interp*);
-    extern int Sqlitetest3_Init(Tcl_Interp*);
-    extern int Sqlitetest4_Init(Tcl_Interp*);
-    extern int Sqlitetest5_Init(Tcl_Interp*);
-    extern int Sqlitetest6_Init(Tcl_Interp*);
-    extern int Sqlitetest7_Init(Tcl_Interp*);
-    extern int Sqlitetest8_Init(Tcl_Interp*);
-    extern int Sqlitetest9_Init(Tcl_Interp*);
-    extern int Sqlitetestasync_Init(Tcl_Interp*);
-    extern int Sqlitetest_autoext_Init(Tcl_Interp*);
-    extern int Sqlitetest_blob_Init(Tcl_Interp*);
-    extern int Sqlitetest_demovfs_Init(Tcl_Interp *);
-    extern int Sqlitetest_func_Init(Tcl_Interp*);
-    extern int Sqlitetest_hexio_Init(Tcl_Interp*);
-    extern int Sqlitetest_init_Init(Tcl_Interp*);
-    extern int Sqlitetest_malloc_Init(Tcl_Interp*);
-    extern int Sqlitetest_mutex_Init(Tcl_Interp*);
-    extern int Sqlitetestschema_Init(Tcl_Interp*);
-    extern int Sqlitetestsse_Init(Tcl_Interp*);
-    extern int Sqlitetesttclvar_Init(Tcl_Interp*);
-    extern int Sqlitetestfs_Init(Tcl_Interp*);
-    extern int SqlitetestThread_Init(Tcl_Interp*);
-    extern int SqlitetestOnefile_Init();
-    extern int SqlitetestOsinst_Init(Tcl_Interp*);
-    extern int Sqlitetestbackup_Init(Tcl_Interp*);
-    extern int Sqlitetestintarray_Init(Tcl_Interp*);
-    extern int Sqlitetestvfs_Init(Tcl_Interp *);
-    extern int Sqlitetestrtree_Init(Tcl_Interp*);
-    extern int Sqlitequota_Init(Tcl_Interp*);
-    extern int Sqlitemultiplex_Init(Tcl_Interp*);
-    extern int SqliteSuperlock_Init(Tcl_Interp*);
-    extern int SqlitetestSyscall_Init(Tcl_Interp*);
-#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
-    extern int TestSession_Init(Tcl_Interp*);
-#endif
-    extern int Fts5tcl_Init(Tcl_Interp *);
-    extern int SqliteRbu_Init(Tcl_Interp*);
-    extern int Sqlitetesttcl_Init(Tcl_Interp*);
-#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
-    extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
-#endif
-
-#ifdef SQLITE_ENABLE_ZIPVFS
-    extern int Zipvfs_Init(Tcl_Interp*);
-    Zipvfs_Init(interp);
-#endif
-
-    Sqliteconfig_Init(interp);
-    Sqlitetest1_Init(interp);
-    Sqlitetest2_Init(interp);
-    Sqlitetest3_Init(interp);
-    Sqlitetest4_Init(interp);
-    Sqlitetest5_Init(interp);
-    Sqlitetest6_Init(interp);
-    Sqlitetest7_Init(interp);
-    Sqlitetest8_Init(interp);
-    Sqlitetest9_Init(interp);
-    Sqlitetestasync_Init(interp);
-    Sqlitetest_autoext_Init(interp);
-    Sqlitetest_blob_Init(interp);
-    Sqlitetest_demovfs_Init(interp);
-    Sqlitetest_func_Init(interp);
-    Sqlitetest_hexio_Init(interp);
-    Sqlitetest_init_Init(interp);
-    Sqlitetest_malloc_Init(interp);
-    Sqlitetest_mutex_Init(interp);
-    Sqlitetestschema_Init(interp);
-    Sqlitetesttclvar_Init(interp);
-    Sqlitetestfs_Init(interp);
-    SqlitetestThread_Init(interp);
-    SqlitetestOnefile_Init();
-    SqlitetestOsinst_Init(interp);
-    Sqlitetestbackup_Init(interp);
-    Sqlitetestintarray_Init(interp);
-    Sqlitetestvfs_Init(interp);
-    Sqlitetestrtree_Init(interp);
-    Sqlitequota_Init(interp);
-    Sqlitemultiplex_Init(interp);
-    SqliteSuperlock_Init(interp);
-    SqlitetestSyscall_Init(interp);
-#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
-    TestSession_Init(interp);
-#endif
-    Fts5tcl_Init(interp);
-    SqliteRbu_Init(interp);
-    Sqlitetesttcl_Init(interp);
-
-#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
-    Sqlitetestfts3_Init(interp);
-#endif
-
-    Tcl_CreateObjCommand(
-        interp, "load_testfixture_extensions", init_all_cmd, 0, 0
-    );
-    Tcl_CreateObjCommand(
-        interp, "db_use_legacy_prepare", db_use_legacy_prepare_cmd, 0, 0
-    );
-    Tcl_CreateObjCommand(
-        interp, "db_last_stmt_ptr", db_last_stmt_ptr, 0, 0
-    );
-
-#ifdef SQLITE_SSE
-    Sqlitetestsse_Init(interp);
-#endif
-  }
-#endif
-}
-
-/* Needed for the setrlimit() system call on unix */
-#if defined(unix)
-#include <sys/resource.h>
-#endif
 
 #define TCLSH_MAIN main   /* Needed to fake out mktclapp */
 int SQLITE_CDECL TCLSH_MAIN(int argc, char **argv){
   Tcl_Interp *interp;
+  int i;
+  const char *zScript = 0;
+  char zArgc[32];
+#if defined(TCLSH_INIT_PROC)
+  extern const char *TCLSH_INIT_PROC(Tcl_Interp*);
+#endif
 
 #if !defined(_WIN32_WCE)
   if( getenv("BREAK") ){
@@ -4271,17 +3643,6 @@ int SQLITE_CDECL TCLSH_MAIN(int argc, char **argv){
   }
 #endif
 
-  /* Since the primary use case for this binary is testing of SQLite,
-  ** be sure to generate core files if we crash */
-#if defined(SQLITE_TEST) && defined(unix)
-  { struct rlimit x;
-    getrlimit(RLIMIT_CORE, &x);
-    x.rlim_cur = x.rlim_max;
-    setrlimit(RLIMIT_CORE, &x);
-  }
-#endif /* SQLITE_TEST && unix */
-
-
   /* Call sqlite3_shutdown() once before doing anything else. This is to
   ** test that sqlite3_shutdown() can be safely called by a process before
   ** sqlite3_initialize() is. */
@@ -4290,32 +3651,27 @@ int SQLITE_CDECL TCLSH_MAIN(int argc, char **argv){
   Tcl_FindExecutable(argv[0]);
   Tcl_SetSystemEncoding(NULL, "utf-8");
   interp = Tcl_CreateInterp();
+  Sqlite3_Init(interp);
 
-#if TCLSH==2
-  sqlite3_config(SQLITE_CONFIG_SINGLETHREAD);
+  sqlite3_snprintf(sizeof(zArgc), zArgc, "%d", argc-1);
+  Tcl_SetVar(interp,"argc", zArgc, TCL_GLOBAL_ONLY);
+  Tcl_SetVar(interp,"argv0",argv[0],TCL_GLOBAL_ONLY);
+  Tcl_SetVar(interp,"argv", "", TCL_GLOBAL_ONLY);
+  for(i=1; i<argc; i++){
+    Tcl_SetVar(interp, "argv", argv[i],
+        TCL_GLOBAL_ONLY | TCL_LIST_ELEMENT | TCL_APPEND_VALUE);
+  }
+#if defined(TCLSH_INIT_PROC)
+  zScript = TCLSH_INIT_PROC(interp);
 #endif
-
-  init_all(interp);
-  if( argc>=2 ){
-    int i;
-    char zArgc[32];
-    sqlite3_snprintf(sizeof(zArgc), zArgc, "%d", argc-(3-TCLSH));
-    Tcl_SetVar(interp,"argc", zArgc, TCL_GLOBAL_ONLY);
-    Tcl_SetVar(interp,"argv0",argv[1],TCL_GLOBAL_ONLY);
-    Tcl_SetVar(interp,"argv", "", TCL_GLOBAL_ONLY);
-    for(i=3-TCLSH; i<argc; i++){
-      Tcl_SetVar(interp, "argv", argv[i],
-          TCL_GLOBAL_ONLY | TCL_LIST_ELEMENT | TCL_APPEND_VALUE);
-    }
-    if( TCLSH==1 && Tcl_EvalFile(interp, argv[1])!=TCL_OK ){
-      const char *zInfo = Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY);
-      if( zInfo==0 ) zInfo = Tcl_GetStringResult(interp);
-      fprintf(stderr,"%s: %s\n", *argv, zInfo);
-      return 1;
-    }
+  if( zScript==0 ){
+    zScript = tclsh_main_loop();
   }
-  if( TCLSH==2 || argc<=1 ){
-    Tcl_GlobalEval(interp, tclsh_main_loop());
+  if( Tcl_GlobalEval(interp, zScript)!=TCL_OK ){
+    const char *zInfo = Tcl_GetVar(interp, "errorInfo", TCL_GLOBAL_ONLY);
+    if( zInfo==0 ) zInfo = Tcl_GetStringResult(interp);
+    fprintf(stderr,"%s: %s\n", *argv, zInfo);
+    return 1;
   }
   return 0;
 }
diff --git a/src/test_md5.c b/src/test_md5.c
new file mode 100644
index 000000000..b67002686
--- /dev/null
+++ b/src/test_md5.c
@@ -0,0 +1,450 @@
+/*
+** 2017-10-13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains code to implement an MD5 extension to TCL.
+*/
+#include "sqlite3.h"
+#include <stdlib.h>
+#include <string.h>
+#include "sqlite3.h"
+#if defined(INCLUDE_SQLITE_TCL_H)
+# include "sqlite_tcl.h"
+#else
+# include "tcl.h"
+# ifndef SQLITE_TCLAPI
+#  define SQLITE_TCLAPI
+# endif
+#endif
+
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+
+/*
+ * If compiled on a machine that doesn't have a 32-bit integer,
+ * you just set "uint32" to the appropriate datatype for an
+ * unsigned 32-bit integer.  For example:
+ *
+ *       cc -Duint32='unsigned long' md5.c
+ *
+ */
+#ifndef uint32
+#  define uint32 unsigned int
+#endif
+
+struct MD5Context {
+  int isInit;
+  uint32 buf[4];
+  uint32 bits[2];
+  unsigned char in[64];
+};
+typedef struct MD5Context MD5Context;
+
+/*
+ * Note: this code is harmless on little-endian machines.
+ */
+static void byteReverse (unsigned char *buf, unsigned longs){
+        uint32 t;
+        do {
+                t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
+                            ((unsigned)buf[1]<<8 | buf[0]);
+                *(uint32 *)buf = t;
+                buf += 4;
+        } while (--longs);
+}
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+        ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+static void MD5Transform(uint32 buf[4], const uint32 in[16]){
+        register uint32 a, b, c, d;
+
+        a = buf[0];
+        b = buf[1];
+        c = buf[2];
+        d = buf[3];
+
+        MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
+        MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
+        MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
+        MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
+        MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
+        MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
+        MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
+        MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
+        MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
+        MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
+        MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
+        MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
+        MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
+        MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
+        MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
+        MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
+
+        MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
+        MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
+        MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
+        MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
+        MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
+        MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
+        MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
+        MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
+        MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
+        MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
+        MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
+        MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
+        MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
+        MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
+        MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
+        MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
+
+        MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
+        MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
+        MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
+        MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
+        MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
+        MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
+        MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
+        MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
+        MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
+        MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
+        MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
+        MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
+        MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
+        MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
+        MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
+        MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
+
+        MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
+        MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
+        MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
+        MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
+        MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
+        MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
+        MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
+        MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
+        MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
+        MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
+        MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
+        MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
+        MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
+        MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
+        MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
+        MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
+
+        buf[0] += a;
+        buf[1] += b;
+        buf[2] += c;
+        buf[3] += d;
+}
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+static void MD5Init(MD5Context *ctx){
+        ctx->isInit = 1;
+        ctx->buf[0] = 0x67452301;
+        ctx->buf[1] = 0xefcdab89;
+        ctx->buf[2] = 0x98badcfe;
+        ctx->buf[3] = 0x10325476;
+        ctx->bits[0] = 0;
+        ctx->bits[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+static
+void MD5Update(MD5Context *ctx, const unsigned char *buf, unsigned int len){
+        uint32 t;
+
+        /* Update bitcount */
+
+        t = ctx->bits[0];
+        if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
+                ctx->bits[1]++; /* Carry from low to high */
+        ctx->bits[1] += len >> 29;
+
+        t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
+
+        /* Handle any leading odd-sized chunks */
+
+        if ( t ) {
+                unsigned char *p = (unsigned char *)ctx->in + t;
+
+                t = 64-t;
+                if (len < t) {
+                        memcpy(p, buf, len);
+                        return;
+                }
+                memcpy(p, buf, t);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+                buf += t;
+                len -= t;
+        }
+
+        /* Process data in 64-byte chunks */
+
+        while (len >= 64) {
+                memcpy(ctx->in, buf, 64);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+                buf += 64;
+                len -= 64;
+        }
+
+        /* Handle any remaining bytes of data. */
+
+        memcpy(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+static void MD5Final(unsigned char digest[16], MD5Context *ctx){
+        unsigned count;
+        unsigned char *p;
+
+        /* Compute number of bytes mod 64 */
+        count = (ctx->bits[0] >> 3) & 0x3F;
+
+        /* Set the first char of padding to 0x80.  This is safe since there is
+           always at least one byte free */
+        p = ctx->in + count;
+        *p++ = 0x80;
+
+        /* Bytes of padding needed to make 64 bytes */
+        count = 64 - 1 - count;
+
+        /* Pad out to 56 mod 64 */
+        if (count < 8) {
+                /* Two lots of padding:  Pad the first block to 64 bytes */
+                memset(p, 0, count);
+                byteReverse(ctx->in, 16);
+                MD5Transform(ctx->buf, (uint32 *)ctx->in);
+
+                /* Now fill the next block with 56 bytes */
+                memset(ctx->in, 0, 56);
+        } else {
+                /* Pad block to 56 bytes */
+                memset(p, 0, count-8);
+        }
+        byteReverse(ctx->in, 14);
+
+        /* Append length in bits and transform */
+        memcpy(ctx->in + 14*4, ctx->bits, 8);
+
+        MD5Transform(ctx->buf, (uint32 *)ctx->in);
+        byteReverse((unsigned char *)ctx->buf, 4);
+        memcpy(digest, ctx->buf, 16);
+}
+
+/*
+** Convert a 128-bit MD5 digest into a 32-digit base-16 number.
+*/
+static void MD5DigestToBase16(unsigned char *digest, char *zBuf){
+  static char const zEncode[] = "0123456789abcdef";
+  int i, j;
+
+  for(j=i=0; i<16; i++){
+    int a = digest[i];
+    zBuf[j++] = zEncode[(a>>4)&0xf];
+    zBuf[j++] = zEncode[a & 0xf];
+  }
+  zBuf[j] = 0;
+}
+
+
+/*
+** Convert a 128-bit MD5 digest into sequency of eight 5-digit integers
+** each representing 16 bits of the digest and separated from each
+** other by a "-" character.
+*/
+static void MD5DigestToBase10x8(unsigned char digest[16], char zDigest[50]){
+  int i, j;
+  unsigned int x;
+  for(i=j=0; i<16; i+=2){
+    x = digest[i]*256 + digest[i+1];
+    if( i>0 ) zDigest[j++] = '-';
+    sqlite3_snprintf(50-j, &zDigest[j], "%05u", x);
+    j += 5;
+  }
+  zDigest[j] = 0;
+}
+
+/*
+** A TCL command for md5.  The argument is the text to be hashed.  The
+** Result is the hash in base64.
+*/
+static int SQLITE_TCLAPI md5_cmd(
+  void*cd,
+  Tcl_Interp *interp,
+  int argc,
+  const char **argv
+){
+  MD5Context ctx;
+  unsigned char digest[16];
+  char zBuf[50];
+  void (*converter)(unsigned char*, char*);
+
+  if( argc!=2 ){
+    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
+        " TEXT\"", (char*)0);
+    return TCL_ERROR;
+  }
+  MD5Init(&ctx);
+  MD5Update(&ctx, (unsigned char*)argv[1], (unsigned)strlen(argv[1]));
+  MD5Final(digest, &ctx);
+  converter = (void(*)(unsigned char*,char*))cd;
+  converter(digest, zBuf);
+  Tcl_AppendResult(interp, zBuf, (char*)0);
+  return TCL_OK;
+}
+
+/*
+** A TCL command to take the md5 hash of a file.  The argument is the
+** name of the file.
+*/
+static int SQLITE_TCLAPI md5file_cmd(
+  void*cd,
+  Tcl_Interp *interp,
+  int argc,
+  const char **argv
+){
+  FILE *in;
+  int ofst;
+  int amt;
+  MD5Context ctx;
+  void (*converter)(unsigned char*, char*);
+  unsigned char digest[16];
+  char zBuf[10240];
+
+  if( argc!=2 && argc!=4 ){
+    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
+        " FILENAME [OFFSET AMT]\"", (char*)0);
+    return TCL_ERROR;
+  }
+  if( argc==4 ){
+    ofst = atoi(argv[2]);
+    amt = atoi(argv[3]);
+  }else{
+    ofst = 0;
+    amt = 2147483647;
+  }
+  in = fopen(argv[1],"rb");
+  if( in==0 ){
+    Tcl_AppendResult(interp,"unable to open file \"", argv[1],
+         "\" for reading", (char*)0);
+    return TCL_ERROR;
+  }
+  fseek(in, ofst, SEEK_SET);
+  MD5Init(&ctx);
+  while( amt>0 ){
+    int n;
+    n = (int)fread(zBuf, 1, sizeof(zBuf)<=amt ? sizeof(zBuf) : amt, in);
+    if( n<=0 ) break;
+    MD5Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
+    amt -= n;
+  }
+  fclose(in);
+  MD5Final(digest, &ctx);
+  converter = (void(*)(unsigned char*,char*))cd;
+  converter(digest, zBuf);
+  Tcl_AppendResult(interp, zBuf, (char*)0);
+  return TCL_OK;
+}
+
+/*
+** Register the four new TCL commands for generating MD5 checksums
+** with the TCL interpreter.
+*/
+int Md5_Init(Tcl_Interp *interp){
+  Tcl_CreateCommand(interp, "md5", (Tcl_CmdProc*)md5_cmd,
+                    MD5DigestToBase16, 0);
+  Tcl_CreateCommand(interp, "md5-10x8", (Tcl_CmdProc*)md5_cmd,
+                    MD5DigestToBase10x8, 0);
+  Tcl_CreateCommand(interp, "md5file", (Tcl_CmdProc*)md5file_cmd,
+                    MD5DigestToBase16, 0);
+  Tcl_CreateCommand(interp, "md5file-10x8", (Tcl_CmdProc*)md5file_cmd,
+                    MD5DigestToBase10x8, 0);
+  return TCL_OK;
+}
+
+/*
+** During testing, the special md5sum() aggregate function is available.
+** inside SQLite.  The following routines implement that function.
+*/
+static void md5step(sqlite3_context *context, int argc, sqlite3_value **argv){
+  MD5Context *p;
+  int i;
+  if( argc<1 ) return;
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( p==0 ) return;
+  if( !p->isInit ){
+    MD5Init(p);
+  }
+  for(i=0; i<argc; i++){
+    const char *zData = (char*)sqlite3_value_text(argv[i]);
+    if( zData ){
+      MD5Update(p, (unsigned char*)zData, (int)strlen(zData));
+    }
+  }
+}
+static void md5finalize(sqlite3_context *context){
+  MD5Context *p;
+  unsigned char digest[16];
+  char zBuf[33];
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  MD5Final(digest,p);
+  MD5DigestToBase16(digest, zBuf);
+  sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
+}
+int Md5_Register(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pThunk
+){
+  int rc = sqlite3_create_function(db, "md5sum", -1, SQLITE_UTF8, 0, 0,
+                                 md5step, md5finalize);
+  sqlite3_overload_function(db, "md5sum", -1);  /* To exercise this API */
+  return rc;
+}
diff --git a/src/test_tclsh.c b/src/test_tclsh.c
new file mode 100644
index 000000000..976f7cb24
--- /dev/null
+++ b/src/test_tclsh.c
@@ -0,0 +1,198 @@
+/*
+** 2017-10-13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains extensions to the the "tclsqlite.c" module used for
+** testing.  Basically, all of the other "test_*.c" modules are linked
+** into the enhanced tclsh used for testing (and named "testfixture" or
+** "testfixture.exe") using logic encoded by this file.
+**
+** The code in this file used to be found in tclsqlite3.c, contained within
+** #if SQLITE_TEST ... #endif.  It is factored out into this separate module
+** in an effort to keep the tclsqlite.c file pure.
+*/
+#include "sqlite3.h"
+#if defined(INCLUDE_SQLITE_TCL_H)
+# include "sqlite_tcl.h"
+#else
+# include "tcl.h"
+# ifndef SQLITE_TCLAPI
+#  define SQLITE_TCLAPI
+# endif
+#endif
+
+/* Needed for the setrlimit() system call on unix */
+#if defined(unix)
+#include <sys/resource.h>
+#endif
+
+/* Forward declaration */
+static int SQLITE_TCLAPI load_testfixture_extensions(
+  ClientData cd,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+);
+
+/*
+** This routine is the primary export of this file.
+**
+** Configure the interpreter passed as the first argument to have access
+** to the commands and linked variables that make up:
+**
+**   * the [sqlite3] extension itself,
+**
+**   * If SQLITE_TCLMD5 or SQLITE_TEST is defined, the Md5 commands, and
+**
+**   * If SQLITE_TEST is set, the various test interfaces used by the Tcl
+**     test suite.
+*/
+const char *sqlite3TestInit(Tcl_Interp *interp){
+  extern int Sqlite3_Init(Tcl_Interp*);
+  extern int Sqliteconfig_Init(Tcl_Interp*);
+  extern int Sqlitetest1_Init(Tcl_Interp*);
+  extern int Sqlitetest2_Init(Tcl_Interp*);
+  extern int Sqlitetest3_Init(Tcl_Interp*);
+  extern int Sqlitetest4_Init(Tcl_Interp*);
+  extern int Sqlitetest5_Init(Tcl_Interp*);
+  extern int Sqlitetest6_Init(Tcl_Interp*);
+  extern int Sqlitetest7_Init(Tcl_Interp*);
+  extern int Sqlitetest8_Init(Tcl_Interp*);
+  extern int Sqlitetest9_Init(Tcl_Interp*);
+  extern int Sqlitetestasync_Init(Tcl_Interp*);
+  extern int Sqlitetest_autoext_Init(Tcl_Interp*);
+  extern int Sqlitetest_blob_Init(Tcl_Interp*);
+  extern int Sqlitetest_demovfs_Init(Tcl_Interp *);
+  extern int Sqlitetest_func_Init(Tcl_Interp*);
+  extern int Sqlitetest_hexio_Init(Tcl_Interp*);
+  extern int Sqlitetest_init_Init(Tcl_Interp*);
+  extern int Sqlitetest_malloc_Init(Tcl_Interp*);
+  extern int Sqlitetest_mutex_Init(Tcl_Interp*);
+  extern int Sqlitetestschema_Init(Tcl_Interp*);
+  extern int Sqlitetestsse_Init(Tcl_Interp*);
+  extern int Sqlitetesttclvar_Init(Tcl_Interp*);
+  extern int Sqlitetestfs_Init(Tcl_Interp*);
+  extern int SqlitetestThread_Init(Tcl_Interp*);
+  extern int SqlitetestOnefile_Init();
+  extern int SqlitetestOsinst_Init(Tcl_Interp*);
+  extern int Sqlitetestbackup_Init(Tcl_Interp*);
+  extern int Sqlitetestintarray_Init(Tcl_Interp*);
+  extern int Sqlitetestvfs_Init(Tcl_Interp *);
+  extern int Sqlitetestrtree_Init(Tcl_Interp*);
+  extern int Sqlitequota_Init(Tcl_Interp*);
+  extern int Sqlitemultiplex_Init(Tcl_Interp*);
+  extern int SqliteSuperlock_Init(Tcl_Interp*);
+  extern int SqlitetestSyscall_Init(Tcl_Interp*);
+#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+  extern int TestSession_Init(Tcl_Interp*);
+#endif
+  extern int Md5_Init(Tcl_Interp*);
+  extern int Fts5tcl_Init(Tcl_Interp *);
+  extern int SqliteRbu_Init(Tcl_Interp*);
+  extern int Sqlitetesttcl_Init(Tcl_Interp*);
+#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
+  extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
+#endif
+#ifdef SQLITE_ENABLE_ZIPVFS
+  extern int Zipvfs_Init(Tcl_Interp*);
+#endif
+  Tcl_CmdInfo cmdInfo;
+
+  /* Since the primary use case for this binary is testing of SQLite,
+  ** be sure to generate core files if we crash */
+#if defined(unix)
+  { struct rlimit x;
+    getrlimit(RLIMIT_CORE, &x);
+    x.rlim_cur = x.rlim_max;
+    setrlimit(RLIMIT_CORE, &x);
+  }
+#endif /* unix */
+
+  if( Tcl_GetCommandInfo(interp, "sqlite3", &cmdInfo)==0 ){
+    Sqlite3_Init(interp);
+  }
+#ifdef SQLITE_ENABLE_ZIPVFS
+  Zipvfs_Init(interp);
+#endif
+  Md5_Init(interp);
+  Sqliteconfig_Init(interp);
+  Sqlitetest1_Init(interp);
+  Sqlitetest2_Init(interp);
+  Sqlitetest3_Init(interp);
+  Sqlitetest4_Init(interp);
+  Sqlitetest5_Init(interp);
+  Sqlitetest6_Init(interp);
+  Sqlitetest7_Init(interp);
+  Sqlitetest8_Init(interp);
+  Sqlitetest9_Init(interp);
+  Sqlitetestasync_Init(interp);
+  Sqlitetest_autoext_Init(interp);
+  Sqlitetest_blob_Init(interp);
+  Sqlitetest_demovfs_Init(interp);
+  Sqlitetest_func_Init(interp);
+  Sqlitetest_hexio_Init(interp);
+  Sqlitetest_init_Init(interp);
+  Sqlitetest_malloc_Init(interp);
+  Sqlitetest_mutex_Init(interp);
+  Sqlitetestschema_Init(interp);
+  Sqlitetesttclvar_Init(interp);
+  Sqlitetestfs_Init(interp);
+  SqlitetestThread_Init(interp);
+  SqlitetestOnefile_Init();
+  SqlitetestOsinst_Init(interp);
+  Sqlitetestbackup_Init(interp);
+  Sqlitetestintarray_Init(interp);
+  Sqlitetestvfs_Init(interp);
+  Sqlitetestrtree_Init(interp);
+  Sqlitequota_Init(interp);
+  Sqlitemultiplex_Init(interp);
+  SqliteSuperlock_Init(interp);
+  SqlitetestSyscall_Init(interp);
+#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+  TestSession_Init(interp);
+#endif
+  Fts5tcl_Init(interp);
+  SqliteRbu_Init(interp);
+  Sqlitetesttcl_Init(interp);
+
+#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
+  Sqlitetestfts3_Init(interp);
+#endif
+
+  Tcl_CreateObjCommand(
+      interp, "load_testfixture_extensions", load_testfixture_extensions,0,0
+  );
+  return 0;
+}
+
+/* tclcmd:   load_testfixture_extensions
+*/
+static int SQLITE_TCLAPI load_testfixture_extensions(
+  ClientData cd,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+
+  Tcl_Interp *slave;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SLAVE");
+    return TCL_ERROR;
+  }
+
+  slave = Tcl_GetSlave(interp, Tcl_GetString(objv[1]));
+  if( !slave ){
+    return TCL_ERROR;
+  }
+
+  (void)sqlite3TestInit(slave);
+  return TCL_OK;
+}
diff --git a/src/where.c b/src/where.c
index 5a3d44f9e..6021edf47 100644
--- a/src/where.c
+++ b/src/where.c
@@ -1885,18 +1885,19 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
 ** Return TRUE if all of the following are true:
 **
 **   (1)  X has the same or lower cost that Y
-**   (2)  X is a proper subset of Y
-**   (3)  X skips at least as many columns as Y
-**
-** By "proper subset" we mean that X uses fewer WHERE clause terms
-** than Y and that every WHERE clause term used by X is also used
-** by Y.
+**   (2)  X uses fewer WHERE clause terms than Y
+**   (3)  Every WHERE clause term used by X is also used by Y
+**   (4)  X skips at least as many columns as Y
+**   (5)  If X is a covering index, than Y is too
 **
+** Conditions (2) and (3) mean that X is a "proper subset" of Y.
 ** If X is a proper subset of Y then Y is a better choice and ought
 ** to have a lower cost.  This routine returns TRUE when that cost 
-** relationship is inverted and needs to be adjusted.  The third rule
+** relationship is inverted and needs to be adjusted.  Constraint (4)
 ** was added because if X uses skip-scan less than Y it still might
-** deserve a lower cost even if it is a proper subset of Y.
+** deserve a lower cost even if it is a proper subset of Y.  Constraint (5)
+** was added because a covering index probably deserves to have a lower cost
+** than a non-covering index even if it is a proper subset.
 */
 static int whereLoopCheaperProperSubset(
   const WhereLoop *pX,       /* First WhereLoop to compare */
@@ -1918,6 +1919,10 @@ static int whereLoopCheaperProperSubset(
     }
     if( j<0 ) return 0;  /* X not a subset of Y since term X[i] not used by Y */
   }
+  if( (pX->wsFlags&WHERE_IDX_ONLY)!=0 
+   && (pY->wsFlags&WHERE_IDX_ONLY)==0 ){
+    return 0;  /* Constraint (5) */
+  }
   return 1;  /* All conditions meet */
 }